'Electric Paint' May Speed Prototyping

Leave it to art students to create an electronic paint. Former students from the Royal College of Art and Imperial College London have devised a conductive ink.

Have you ever wished you could draw a wire on your PCB, erase another, or fix your broken circuit with a pen? Dream no more! You just need a bit of Bare Conductive's "Electric Paint."

This revolutionary product was started as a student project among undergrads at the Royal College of Art and Imperial College London, where Bare Conductive founders Isabel Lizardi, Matt Johnson, Bibi Nelson, and Becky Pilditch were looking for a way to print an electric circuit on the body. They developed a safe, easy-to-use ink and now market it as Electric Paint.

This group of designers and engineers combined their skills to develop a product that can be used for many applications, but it is especially appealing to education and electronics enthusiasts.

Electric Paint can be used as a liquid wire to draw or print graphical circuits, or even as a conductive adhesive eliminating the need for soldering equipment... Electric Paint can be used alongside electrical components, prototyping materials, PCBs, microcontrollers (Arduino, Raspberry Pi, MaKey MaKey, LilyPad, FLORA), e-textiles, and conductive thread.

Electric Paint is available in 10 ml pens, 50 ml jars, and 1 liter tubs. You can just buy a pen that looks like your standard broad marker for £6 ($10) and start drawing circuits on a piece of paper or on your wall. It has a resistance of 55 Ω/Sq @ 50 microns, and it is not recommended for voltages over 12 v DC.

Painting a sensor with Electric Paint. (Source: Bare Conductive)

One of the key features of Electric Paint is that it is not conductive until it dries. The paint dries fast at room temperature and releases no fumes during the process. It complies with the EU's RoHS regulations about the use of hazardous substances.

Electric Paint is also flexible, but this flexibility depends on how thickly it is applied and to what type of material. Paper usually works better than surfaces that stretch in different directions. Currently, the paint is only available in black (it could be useful to have different colors to play with) but can be coated with other materials while still retaining its properties. It is also great as a conductive adhesive and could be used on plastic and other materials where a soldering iron wouldn't work. Multilayer circuits are also possible if used in conjunction with acrylic-based paints to act as an insulator.

The paint's properties do not degrade. We advise the paint is used within six months of opening, just to avoid drying out. The longevity of a fix totally depends on what material the paint is applied to and how. If a surface is particularly glossy, the paint can peel off or crack, and the same can happen with a fabric or paper that is constantly being flexed and bent. In general, the paint adheres to other surfaces very well and should work fine for fixing small PCB or electronic models.

Since it is primarily geared toward education, the developers took special care to make it non-toxic, child safe, solvent free, and water soluble -- great for the classroom. The company is also introducing a board, called Touch Board, with which to create sensors using the ink. It begins shipping June 30, 2014, according to the company's website.

The product is available from Bare Conductive's website and at RadioShack, ThinkGeek, and other resellers in the US, plus some museums, such as The Exploratorium in San Francisco. It ships worldwide.

— Pablo Valerio is a freelance blogger who writes about mobile and telecom issues for EE Times He lives and works in Spain.